Trying to find an oxide removing pen/stick for soldering corroded components

[richnormand]

This is what I use:

Nail polisher. Variable speed and rotation direction. Battery powered. Cheap on ebay.
Assortment of diamond files and such, for the nail polisher.
Assortment of dentist tools, the scraper wedges in particular. The hand feel and dexterity is much better than a Dremel for me for a light touch.
A fiberglass pen. The brass spikes and others are too damaging and big for fine work.
Clean with IPA when done and put a drop of flux before tinning.

All done under a real 3D binocular microscope meant for medical dissection.

Hope this helps.